From the higher resolution images on the other Xs thread, one can also tell which brand/type was used in either amp case.
(don't let any power JFET semiMouth jokes there distract you, just fun to fool around with all things relative)

The resolution of the inside pics of Xs amps needs improvement. buzzforb may disagree; noting that somebody/somewhere will thus unravel the secrets of what makes a Pass amp sound so awesome. Who else on our planet is in a position [of expertise and know-how etc.] or gives a damn like Mr. Pass to create this awesomeness? Besides; a clear picture is a beast of a thousand words. Why then hide all the art and beauty? Are there fake copies of Pass commercial amps? Never heard of them. Fuzzy pictures are still welcome, and will make my quest to understand Xs a welcome challenge.